• ETRI Journal
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• 제33권3호
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• pp.299-309
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• 2011

Energy consumption is a key issue in body sensor networks (BSNs) since energy-constrained sensors monitor the vital signs of human beings in healthcare applications. In this paper, packet size optimization for BSNs has been analyzed to improve the efficiency of energy consumption. Existing studies on packet size optimization in wireless sensor networks cannot be applied to BSNs because the different operational characteristics of nodes and the channel effects of in-body and on-body propagation cannot be captured. In this paper, automatic repeat request (ARQ), forward error correction (FEC) block codes, and FEC convolutional codes have been analyzed regarding their energy efficiency. The hop-length extension technique has been applied to improve this metric with FEC block codes. The theoretical analysis and the numerical evaluations reveal that exploiting FEC schemes improves the energy efficiency, increases the optimal payload packet size, and extends the hop length for all scenarios for in-body and on-body propagation.

• 한국정보통신학회논문지
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• 제18권8호
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• pp.1961-1972
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• 2014

최근 들어 정보통신기술과 의료기술의 통합에 관한 관심이 증가되면서 센서네트워크를 인체에 적용하고자 하는 WBAN(Wireless Body Area Networks)에 관한 연구가 활발히 진행되고 있다. 기존의 센서네트워크 기술은 WBAN에 이용될 수 있는 가능성을 가지고 있으나, 몇 가지 제약사항을 가지고 있다. 특히 신체의 각 센서는 신체의 각 부분을 관통하여 통신해야 할 가능성이 크므로 자유공간인 센서네트워크와는 상당히 다른 네트워킹 환경을 가진다. 따라서 WBAN에 관한 연구는 기존의 센서네트워크와는 다른 인체의 특성을 고려한 다양한 영역을 연구의 대상으로 하고 있다. 본 연구에서는 기존의 센서네트워크와는 다른 WBAN의 환경적인 특성을 조사하고, WBAN의 개념이 도입된 2001년 전후부터 SLR(Systematic Literature Review)기법을 이용하여 WBAN의 연구 경향을 체계적으로 조사한다. 이에는 연구 분류와 연구자의 특성 등이 포함된다. 조사 결과를 요약하고 향후 연구 과제를 전망한다.

• Journal of Communications and Networks
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• 제13권2호
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• pp.160-166
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• 2011

In u-healthcare services based on wireless body sensor networks, reliable connection is very important as many types of information, including vital signals, are transmitted through the networks. The transmit power requirements are very stringent in the case of in-body networks for implant communication. Furthermore, the wireless link in an in-body environment has a high degree of path loss (e.g., the path loss exponent is around 6.2 for deep tissue). Because of such inherently bad settings of the communication nodes, a multi-hop network topology is preferred in order to meet the transmit power requirements and to increase the battery lifetime of sensor nodes. This will ensure that the live body of a patient receiving the healthcare service has a reduced level of specific absorption ratio (SAR) when exposed to long-lasting radiation. We propose an efficientmethod for delivering delay-intolerant data packets over multiple hops. We consider forward error correction (FEC) in an erasure correction mode and develop a mathematical formulation for packet-level scheduling of delay-intolerant FEC packets over multiple hops. The proposed method can be used as a simple guideline for applications to setting up a topology for a medical body sensor network of each individual patient, which is connected to a remote server for u-healthcare service applications.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제5권6호
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• pp.127-134
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• 2016

무선인체센서네트워크(WBSN: Wireless Body Sensor Network)은 일반적으로 무선인체네트워크(WBAN: Wireless Body Area Networks)라고도 불리는데, 일종의 무선센서네트워크(WSN: Wireless Sensor Network)의 응용 중에 하나로, 인간의 신체에 이식되거나 착용하는 형태의 감지노드들로 인체 가까이에 설치된다. WBSN에 설치된 각 노드로부터 측정된 데이터는 싱크 노드에서 인체 상태를 분석하기 위하여 사용되는데, 다른 무선센서네트워크 응용과 마찬가지로 노드와 싱크 노드는 서로 동기화되어야 한다. 무선센터네트워크에서 동작하는 여러시각 동기화 프로토콜이 제안되어왔으나 WBSN에 적용하기에는 부적합하다. 이 논문에서는 WBSN의 특성을 고려하여 새로운 시각 동기화 프로토콜을 제안한다. 제안한 프로토콜은 간단할뿐만 아니라 전력 소모가 작아 네트워크의 수명을 오랫동안 유지할 수 있게 한다. 제안 방안의 성능을 시뮬레이션을 통해 평가하였으며, WBSN에서 구현하기에 적합함을 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.1014-1035
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• 2013

With recent advances in wireless communication and low-power miniaturized biomedical sensor and semiconductor technologies, wireless body area networks (WBAN) has become an integral part of the disaster aid system. Wearable vital sign sensors can track patients' status and location, thus enhancing disaster rescue efficiency. In the past few years, most of the literatures in the area of disaster aid system based on WBAN have focused on issues concerning wireless sensor design, sensor miniaturization, energy efficiency and communication protocols. In this paper, we will give an overview of disaster aid, discuss about the types of network communication as well as outline related issues. We will emphasize on analyzing six key issues in employing the disaster aid system. Finally, we will also highlight some of the challenges that still need to be addressed in the future in order to help the disaster aid system be truly and widely accepted by the public.

• Journal of information and communication convergence engineering
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• 제17권2호
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• pp.105-116
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• 2019

Recently, there has been an increase in research on wireless sensor networks (WSNs) because they are easy to deploy in applications such as internet-of-things (IoT) and body area networks. However, WSNs have constraints in terms of power, quality-of-service (QoS), computation, and others. To overcome the power constraint issues, wireless energy harvesting has been introduced into WSNs, the application of which has been the focus of many studies. Additionally, to improve system performance in terms of achievable rate, cooperative networks are also being explored in WSNs. We present a review on current research in the area of energy harvesting in WSNs, specifically on the application of simultaneous wireless information and power transfer (SWIPT) in a cooperative sensor network. In addition, we discuss possible future extensions of SWIPT and cooperative networks in WSNs.

• 스마트미디어저널
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• 제3권1호
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• pp.28-32
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• 2014

It is practical nowadays to automate data recording in order to prevent loss and tampering of records. There are existing technologies that satisfy this needs and one of them is wireless sensor networks (WSN). Wireless body sensor networks (WBSN) are wireless networks and information-processing systems which are deployed to monitor medical condition of patients. In terms of performance, WBSNs are restricted by energy, and communication between nodes. In this paper, we focused in improving the performance of communication to achieve less energy consumption and to save power. The main idea of this paper is to prioritize nodes that exhibit a sudden change of vital signs that could put the patient at risk. Cluster head is the main focus of this study in order to be effective; its main role is to check the sent data of the patient that exceeds threshold then transfer to the sink node. The proposed scheme implemented added a time-based protocol to sleep/wakeup mechanism for the sensor nodes. We seek to achieve a low energy consumption and significant throughput in this study.

• ETRI Journal
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• 제43권1호
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• pp.31-39
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• 2021

One of the major challenges in wireless body area networks (WBANs) is sensor fault detection. This paper reports a method for the precise identification of faulty sensors, which should help users identify true medical conditions and reduce the rate of false alarms, thereby improving the quality of services offered by WBANs. The proposed sensor fault detection (SFD) algorithm is based on Pearson correlation coefficients and simple statistical methods. The proposed method identifies strongly correlated parameters using Pearson correlation coefficients, and the proposed SFD algorithm detects faulty sensors. We validated the proposed SFD algorithm using two datasets from the Multiparameter Intelligent Monitoring in Intensive Care database and compared the results to those of existing methods. The time complexity of the proposed algorithm was also compared to that of existing methods. The proposed algorithm achieved high detection rates and low false alarm rates with accuracies of 97.23% and 93.99% for Dataset 1 and Dataset 2, respectively.

• Journal of Computing Science and Engineering
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• 제4권1호
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• pp.23-51
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• 2010

Wireless Sensor Networks (WSN) have proved to be useful in applications that involve monitoring of real-time data. There is a wide variety of monitoring applications that can employ Wireless Sensor Network. Characteristics of a WSN, such as topology and scale, depend upon the application, for which it is employed. Security requirements in WSN vary according to the application dependent network characteristics and the characteristics of an application itself. Key management is the most important aspect of security as some other security modules depend on it. We discuss application dependent variations in WSN, corresponding changes in the security requirements of WSN and the applicability of existing key management solutions in each scenario.

• Journal of Communications and Networks
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• 제17권5호
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• pp.453-462
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• 2015

Body area networks (BANs) have emerged as an enabling technique for e-healthcare systems, which can be used to continuously and remotely monitor patients' health. In BANs, the data of a patient's vital body functions and movements can be collected by small wearable or implantable sensors and sent using shortrange wireless communication techniques. Due to the shared wireless medium between the sensors in BANs, it may be possible to have malicious attacks on e-healthcare systems. The security and privacy issues of BANs are becoming more and more important. To provide secure and correct association of a group of sensors with a patient and satisfy the requirements of data confidentiality and integrity in BANs, we propose a novel enhanced secure sensor association and key management protocol based on elliptic curve cryptography and hash chains. The authentication procedure and group key generation are very simple and efficient. Therefore, our protocol can be easily implemented in the power and resource constrained sensor nodes in BANs. From a comparison of results, furthermore, we can conclude that the proposed protocol dramatically reduces the computation and communication cost for the authentication and key derivation compared with previous protocols. We believe that our protocol is attractive in the application of BANs.